Blood Cell Separator Research Articles

Efficient granulocyte collection method using high concentrations of medium molecular weight hydroxyethyl starch.

Granulocyte transfusion therapy is a rational therapeutic option for patients with prolonged, severe neutropenia. Although high molecular weight hydroxyethyl starch (hHES) facilitates the separation of red blood cells during granulocyte collection, renal dysfunction has been noted as a potential side effect. HES130/0.4 (Voluven®) is a medium molecular weight HES (mHES) with superior safety profiles compared to hHES. Although HES130/0.4 is reportedly effective in the collection of granulocytes, we lack studies comparing the efficiency of granulocyte collection using HES130/0.4 and hHES. We retrospectively collected the data from 60 consecutive apheresis procedures performed on 40 healthy donors at the Okayama University Hospital between July 2013 and December 2021. All procedures were performed using the Spectra Optia system. Based on the HES130/0.4 concentration in the separation chamber, granulocyte collection methods using HES130/0.4 were classified into m0.46, m0.44, m0.37, and m0.8 groups. We used HES130/0.4 and hHES groups to compare the various sample collection methods. The median granulocyte collection efficiency (CE) was approximately 24.0% and 28.1% in the m0.8 and hHES groups, respectively, which were significantly higher than those in the m0.46, m0.44, and m0.37 groups. One month following granulocyte collection with HES130/0.4, no significant changes were observed in serum creatinine levels compared to those before the donation. Therefore, we propose a granulocyte collection approach employing HES130/0.4, which is comparable to the use of hHES in terms of the granulocyte CE. A high concentration of HES130/0.4 in the separation chamber was considered crucial for granulocyte collection.

Numerical and experimental investigation of high-resolution manipulation of microparticles using a developed two-stage acoustofluidic platform

Acoustophoresis as an emerging label-free, biocompatible, and contactless technique in particle separation has attracted recent interest in the separation of cells and particles from heterogeneous samples. Improving separation resolution in many biological applications in which particles of close sizes must be separated is of great importance. To study the separation of microparticles with similar sizes, a two-stage acoustofluidic platform is developed in this study. The device uses acoustic and hydrodynamic focusing mechanisms to boost alignment efficiency in its first stage. The device's second module separates microparticles using standing acoustic waves. In both numerical and experimental studies, multiple parameters such as geometrical features, pressure distribution, and sheath-flow variation were investigated to optimize separation performance. The experimental results show that particles of sizes 8–10 µm can be separated with a purity of more than 80% and a throughput of 10 µl/min. As a potential application, the separation resolution demonstrated in the study can be applied to the separation of white blood cells, e.g., neutrophils from leukocytes.

Modeling non-Newtonian magnetized blood circulation with tri-nanoadditives in a charged artery

Recently, the radical evolution in the mechanism of micro-scale transport has been expedited due to their applications relating to the examination of biological and chemical samples, species control separation, blood cell separation, drug delivery, etc. In this research article, a new mathematical model is set up for searching the hydro-thermal transport functioning of non-Newtonian ionized modified hybrid nano blood (MHNB) inside a charged artery with a sinusoidal wall in an electromagnetic ambience. The rheological behaviours of blood infused with tri-nanoparticles (copper, gold and alumina) are mimicked by adopting the Casson liquid scheme’s relations. The frictional and Joule heating terms are featured in the thermal transport equation. The Poisson-Boltzmann equation is employed in determining the charge spreading in the electric double layer (EDL) due to the occurrence of an electric field aligned axially. The simplified model equations are retrieved as a result of Debye-Hückel linearization (DHL) and lubrication approximations and subsequently solved in closed forms. To cover all aspects of the modelling and analysis, the hemodynamical behaviours of blood circulation are graphed in the form of line and bar graphs, and the significant contributions of governed flow factors are illustrated with physical explications. Moreover, numerical outcomes of arterial wall shear stress are tabulated to analyze the dominance of related parameters on it. Based on the graphical simulations, it is perceived that the electro-osmotic factors control the dynamism of blood in the artery. A low-pressure gradient is recorded for modified hybrid nano bloodstream as compared to pure bloodstream. The heat transfer coefficient substantially enhances for larger fractional amounts of nanoparticles suffused with blood. The key findings of the present simulation could meet the nearing challenges in future biotechnologies.

Continuous Flow Separation of Red Blood Cells and Platelets in a Y-Microfluidic Channel Device with Saw-Tooth Profile Electrodes via Low Voltage Dielectrophoresis

Cell counting and sorting is a vital step in the purification process within the area of biomedical research. It has been widely reported and accepted that the use of hydrodynamic focusing in conjunction with the application of a dielectrophoretic (DEP) force allows efficient separation of biological entities such as platelets from red blood cell (RBC) samples due to their size difference. This paper presents computational results of a multiphysics simulation modelling study on evaluating continuous separation of RBCs and platelets in a microfluidic device design with saw-tooth profile electrodes via DEP. The theoretical cell particle trajectory, particle cell counting, and particle separation distance study results reported in this work were predicted using COMSOL v6.0 Multiphysics simulation software. To validate the numerical model used in this work for the reported device design, we first developed a simple y-channel microfluidic device with square "in fluid" electrodes similar to the design reported previously in other works. We then compared the obtained simulation results for the simple y-channel device with the square in fluid electrodes to the reported experimental work done on this simple design which resulted in 98% agreement. The design reported in this work is an improvement over existing designs in that it can perform rapid separation of RBCs (estimated 99% purification) and platelets in a total time of 6-7 s at a minimum voltage setting of 1 V and at a minimum frequency of 1 Hz. The threshold for efficient separation of cells ends at 1000 kHz for a 1 V setting. The saw-tooth electrode profile appears to be an improvement over existing designs in that the sharp corners reduced the required horizontal distance needed for separation to occur and contributed to a non-uniform DEP electric field. The results of this simulation study further suggest that this DEP separation technique may potentially be applied to improve the efficiency of separation processes of biological sample scenarios and simultaneously increase the accuracy of diagnostic processes via cell counting and sorting.

Recent Development and Applications of Magnetism in Biomedicine

Fluorescence-activated cell sorting (FACS), a cell isolation approach that relies on immunofluorescent signals, is among the most frequently applied approaches. Due to the inherent advantages of microfluidic devices in terms of small size, short detection time and low cost, their application in biotechnology are currently being investigated. Current research by scholars was reviewed by the literature method. Micro-magnet matrices can be used to move multiple cells in cell manipulation, and open tubular with magnetic trapping bead trap beds can be useful in trapping blood cells. The trapping and separation of blood cells have been better progressed, and future studies can concentrate on the concurrent sorting of several targets at high purity, recovery, and throughput levels, label-free continuous separation of cell mixtures, and the sorting of different cells by changing the device environment around the properties of the magnetic device itself.

Design of a low-voltage dielectrophoresis lab-on-the chip to separate tumor and blood cells

In this paper, we design and propose a compact label-free microfluidic lab-on-a-chip device to separate circulating tumor cells (CTCs) from red blood cells (RBCs) at low voltage to minimize cell damage. With the aim of developing a mm-long device to perform cell separation, we used 3D finite element simulation modeling and investigated separation efficiency for different electrode configurations, electrode shapes, and channel heights. Our results show that configuring the electrodes as two arrays, consisting of only five pairs of top and bottom planar electrodes shifted relative to each other and energized with ± 6 V at 70 kHz, generates sufficient non-uniform electric fields to separate CTCs and RBCs in a 2 mm long channel. The advantage of the proposed design is the simplicity of the electrode arrangement and that the electrodes do not cover the central part of the channel, thus allowing for brightfield imaging of the channel. In addition, the low voltage needed and the 50 µm high channel reduce the Joule heating effect and improve the device's separation and throughput efficiency. We suggest that the proposed design would be effective for separating CTCs and RBCs and, thus, used as a device for the early detection of CTCs.

Separation of bacteria smaller than 4µm from other blood components using insulator-based dielectrophoresis: numerical simulation approach.

Bloodstream infection (BSI) is a life-threatening infection that causes more than 80,000 deaths and more than 500,000 infections annually in North America. The rapid diagnosis of infection reduces BSI mortality. We proposed bacterial enrichment and separation approach in the current work that may reduce culturing time and accelerate the diagnosis of infection. Over the last two decades, multiple separation methods have been developed, and among these methods, insulator-based dielectrophoresis (iDEP) is considered a powerful technique for separating biological particles. Bacterial separation in the blood is challenging due to the presence of other blood cells, such as white blood cells, red blood cells, and platelets. In the present study, a model is presented which is capable of blood cells separation and directing each cell to a specific outlet using continuous flows of particles with sizes larger than 8µm, 8-4µm, and smaller than 4µm. Compared to other methods, such as filtration, the main advantage of this model is that particles larger than 8µm are separated from the flow before other particles, which prevents the accumulation of particles in the channel. The outcomes of simulations demonstrated that the factors such as applied voltage and channel dimensions significantly affect the separation efficiency. If these values are properly selected (for example voltage of 70V that was causing an electric field of 200V/cm), the proposed model can completely (100%) separate particles larger than 8µm and smaller than 4µm (8-4µm particles separation efficiency is 95%).

Analysis and Simulation of Blood Cells Separation in a Polymeric Serpentine Microchannel under Dielectrophoresis Effect

The current work presents a novel microfluidic approach, allowing a full separation of blood cells. The approach relies on using a polydimethylsiloxane serpentine microchannel equipped with a series of electrodes, providing two separation zones. The proposed design exploits the unique configuration of the channel along with the inherent difference in dielectric properties of the three kinds of blood cells to achieve a size-based sorting. The platelets (PLTs) are subjected to a larger dielectrophoretic force than red blood cells (RBCs) and white blood cells (WBCs), forcing them to be separated in the first zone. This leaves RBCs and WBCs to be separated in the second zone. The model developed in this work has been used intensively to examine the feasibility of the proposed approach. The model results showed a full separation of blood content can be achieved over a range of phase flow rates and AC frequencies.

Success rates and clinicopathologic associations with experimental outcomes of a novel circulating tumor cell (CTC) technology in advanced colon cancer (CC) and pancreatic cancer (PC).

805 Background: Studying CTC cultures (cx) ex-vivo can provide valuable insights into cancer metastases (mets). However, current immunoaffinity- and size-based-methods used to isolate and expand these cells have low success rates for culturing CTCs (6-20%). Here, we report our experience using a novel technology developed at Georgetown for culturing CTCs from patients (pts) with metastatic (m) CC, mPC, and locally advanced PC (LAPC). Methods: 44 peripheral blood samples were prospectively collected from 35 pts with adenocarcinoma across 3 cohorts (18 samples from 15 mCC pts, 21 samples from 15 mPC pts, and 5 samples from 5 LAPC pts). Pts were previously treated, treatment-naïve, or actively undergoing treatment. FiColl-Paque-based separation of red blood cells was performed, plasma and buffy coat cells were resuspended in cx medium, and successfully grown CTC cxs were processed and injected subcutaneously (subQ) in the flanks of mice. A single predetermined sample from each pt was used in assessing the clinicopathologic associations with experiment outcomes and survival analyses. Results: CTC cxs were successfully grown from 81.8% (36/44) of all samples. Cxs grew from 72.2% (13/18) of mCC, 85.7% (18/21) of mPC, and 100% (5/5) of LAPC samples. At the time of analysis, 25 injected mice were evaluable for subQ tumor growth. 4 mice failed to grow tumor, 10 were still under monitoring, and 11 grew tumor, 9 of which also developed mets. These were mostly macro-mets and partially mirrored the met pattern seen in the matched pt. Across all cohorts, samples were predominantly collected from pts during systemic treatment (79.5%), during 2nd- (36.4%) and 1st-line treatment (20.5%), at a median of 15 (0-111) and 5 (1-20) months after diagnosis in mPC/mCC and LAPC pts, respectively, after scans with new/progressing disease (72.7%), and with a median of 3 (1-9) sites of disease on scans done within 2 months of collection . In all pts, no clinicopathologic or genomic factor predicted for cx growth. In the mCC subgroup, female sex (p=0.044), longer time from diagnosis to CTC collection (p=0.033), and presence of lung mets (p=0.022) were associated with cx growth. With cohorts combined, the median pt progression-free survival was 174 days (95% CI 97-220) and median overall survival was not reached. There was no statistically significant relationship between cx growth and pt survival. Conclusions: This novel platform demonstrated historically high rates of successful CTC cx and xenograft tumor growth using samples from advanced CC and PC pts. Studies to elucidate reasons for mice failing to grow tumor and others with matched tumor-CTC molecular analyses are ongoing to validate this promising technology to ultimately use to identify biomarkers for metastases, uncover novel therapeutic targets, and inform clinical decisions.

Poly(ethylene oxide) Concentration Gradient-Based Microfluidic Isolation of Circulating Tumor Cells

Circulating tumor cells (CTCs) have emerged as promising circulating biomarkers for non-invasive cancer diagnosis and management. Isolation and detection of CTCs in clinical samples are challenging due to the extreme rarity and high heterogeneity of CTCs. Here, we describe a poly(ethylene oxide) (PEO) concentration gradient-based microfluidic method for rapid, label-free, highly efficient isolation of CTCs directly from whole blood samples. Stable concentration gradients of PEO were formed within the microchannel by co-injecting the side fluid (blood sample spiked with 0.025% PEO) and center fluid (0.075% PEO solution). The competition between the elastic lift force and the inertial lift force enabled size-based separation of large CTCs and small blood cells based on their distinct migration patterns. The microfluidic device could process 1 mL of blood sample in 30 min, with a separation efficiency of >90% and an enrichment ratio of >700 for tumor cells. The isolated CTCs from blood samples were enumerated by immunofluorescence staining, allowing for discrimination of breast cancer patients from healthy donors with an accuracy of 84.2%. The concentration gradient-based microfluidic separation provides a powerful tool for label-free isolation of CTCs for a wide range of clinical applications.

Blood Cell Separation Using Polypropylene-Based Microfluidic Devices Based on Deterministic Lateral Displacement.

Mammalian blood cell separation methods contribute to improving the diagnosis and treatment of animal and human diseases. Microfluidic deterministic lateral displacement (DLD) devices can sort cells based on their particle diameter. We developed microfluidic DLD devices with poly(propylene)-based resin and used them to separate bovine and human red blood cells (RBCs) and white blood cells (WBCs) without electric devices. To determine the critical cut-off diameter (Dc) of these devices, we used immunobeads with a diameter of 1-20 μm. The Dc values of the microfluidic DLD devices for the immunobeads in the experiments were similar to the calculated Dc values (8-10 μm). Results from bovine blood cell separation experiments suggest that lymphocytes and neutrophils can be separated from diluted, whole blood. Human RBCs were occasionally observed in the left outlet where larger particles with diameters closer to the Dc value were collected. Based on the Dc values, human neutrophils were sorted to the left outlet, whereas lymphocytes were observed in both outlets. Although microfluidic channel optimization is required for the concentration of sorted cells, the microfluidic DLD device prepared with a poly(propylene)-based resin has the potential for clinical use.

Microfluidic Systems for Blood and Blood Cell Characterization

A laboratory blood test is vital for assessing a patient's health and disease status. Advances in microfluidic technology have opened the door for on-chip blood analysis. Currently, microfluidic devices can reproduce myriad routine laboratory blood tests. Considerable progress has been made in microfluidic cytometry, blood cell separation, and characterization. Along with the usual clinical parameters, microfluidics makes it possible to determine the physical properties of blood and blood cells. We review recent advances in microfluidic systems for measuring the physical properties and biophysical characteristics of blood and blood cells. Added emphasis is placed on multifunctional platforms that combine several microfluidic technologies for effective cell characterization. The combination of hydrodynamic, optical, electromagnetic, and/or acoustic methods in a microfluidic device facilitates the precise determination of various physical properties of blood and blood cells. We analyzed the physical quantities that are measured by microfluidic devices and the parameters that are determined through these measurements. We discuss unexplored problems and present our perspectives on the long-term challenges and trends associated with the application of microfluidics in clinical laboratories. We expect the characterization of the physical properties of blood and blood cells in a microfluidic environment to be considered a standard blood test in the future.

Development of a hybrid acousto-inertial microfluidic platform for the separation of CTCs from neutrophil

The ability to fast and precise cell separation is a crucial issue for many biomedical applications and diagnoses. Despite several active and passive cell separation methods, high throughput, biocompatible, and label-free techniques are still demanding. High-accuracy acoustic and high-throughput inertial microfluidics can be integrated by combining acoustic and inertial methods. Accordingly, a new solver and two libraries have been developed in OpenFOAM to simulate particle tracking in a two-stage microchannel for focusing and separating particles simultaneously. In the first stage, the different Aspect Ratios (AR) of a serpentine microchannel with four different configurations were simulated in a range of flow rates to achieve the proper particle focusing. The results showed that the square serpentine configuration with AR=0.2 and flow rate of Q=2 ml/min gives a more favorable particle focusing. This channel was then linked to the second-staged straight channel for acoustic separation of breast cancer cells (MCF-7) and neutrophil white blood cells (WBCs). The separation was also compared for standing and traveling surface acoustic waves over a voltage range, and efficiency and purity were obtained for each outlet. At a flow rate of 2 ml/min, which is about four folds higher than the literature, the separation efficiency for MCF-7 cells was 99.3%, and the purity was 93.5% using standing surface acoustic waves (SSAWs). This high-throughput and high-accuracy proposed microfluidic device promises to be used for Lab-on-Chip (LOC) clinical applications for rapid and early detection before cancer metastasis.

Comparison of the efficiency of peripheral blood stem cell apheresis on the blood cell separators.

Stem cells apheresis is a key step in the process of the autologous stem cell transplantation. Available blood cell separators (BCS) have different efficiency due to the technical characteristics and influence of the operator. Retrospectively, data were collected of the peripheral blood stem cells apheresis performed using available BCS manufactured by Fresenius (ComTec and Amicus) in the National Cancer Institute Ukraine from 2017 to 2020. The collection efficiency coefficient (CEC) was calculated, the formula for predicting the total volume of processed blood (TVPB) was adapted for each separator. The analysis included data from 60 patients (total of 92 apheresis procedures). The mean CEC was established at the level of (53.8 ± 36.6) % for the Amicus device and (44.2 ± 37.3) % for the ComTec device; P = 0.22. The lower product volume was obtained using the Amicus device compared to the ComTec device; P = 2×10-7. The amount of collected stem cells was comparable in both groups (5.8 ± 5.7) ×106/kg and (4.1 ± 3.1) ×106/kg, respectively; P = 0.064. The adaptation of the formula for predicting the TVPB to achieve the optimum amount of stem cells was performed. The CEC for each device was within the generally accepted limits of 30-50%, and did not differ significantly. Nevertheless, using of the Amicus BCS allowed to collect lower volumes of the product, maintaining other characteristics of the product competitive.

Experimental Characterization of a Microfluidic Device Based on Passive Crossflow Filters for Blood Fractionation

The separation of red blood cells (RBCs) from blood plasma and the analysis of individual RBCs are of great importance, as they provide valuable information regarding the health of their donor. Recent developments in microfluidics and microfabrication have contributed to the fabrication of microsystems with complex features to promote the separation and analysis of RBCs. In this work, the separation capacity of a multi-step crossflow microfluidic device was evaluated by using a blood analogue fluid made by Brij L4 micelles and human RBCs separated from whole blood, suspended in a solution with hematocrits (Ht) of 0.5 and 1%. All the samples collected at the outlets of the device were experimentally analyzed and compared. The absorbance spectrum was also measured for the prepared blood samples. The results indicate that the tested blood analogue fluid has exhibited a flow behavior similar to that of blood. In addition, the optical absorbance spectrophotometry revealed that it was possible to evaluate the separation efficiency of the microfluidic device, concluding that the concentration of cells was lower at the most lateral outside outlets of the microchannel due to the cumulative effect of the multiple cross-flow filters.

Nanocellulose coated paper diagnostic to measure glucose concentration in human blood.

A new generation of rapid, easy to use and robust colorimetric point of care (POC) nanocellulose coated-paper sensors to measure glucose concentration in blood is presented in this study. The cellulose gel containing the enzyme with co-additive is coated and dried onto a paper substrate. Nanocellulose gel is used to store, immobilize and stabilize enzymes within its structure to prolong enzyme function and enhance its availability. Here, we immobilize glucose oxidase within the gel structure to produce a simple colorimetric blood glucose sensor. Increase in blood glucose concentration increases the concentration of reaction product which decreases the system pH detected by the pH indicative dye entrapped in the nanocellulose gel. The sensor produces a color change from red to orange as pH decreases due to the enzymatic reaction of glucose into gluconic acid and hydrogen peroxide. This sensor can measure glucose concentrations of 7-13mM (medical range for diabetes control) at temperatures of 4°C-40°C. Stability tests confirm that no denaturation of enzyme occurs by measuring enzyme activity after 4weeks. A prototype device is designed to instantly measure the glucose concentration from blood in a two steps process: 1) red blood cell separation and 2) quantification of glucose by color change. This study demonstrates nanocellulose sensor as an economical, robust, and sensitive diagnostic technology platform for a broad spectrum of diseases.

Anti-Myeloma Effect of Compound K and Rh2 in a Multiple Myeloma Xenograft Model

Introduction: Several ginsenosides have demonstrated anti-cancer activity due to their ability to inhibit DNA synthesis and angiopoiesis, inducing cancer death. Rh2, a PPD-type 20(S)-ginsenoside, has been extensively studied as a major ingredient with antineoplastic properties. Moreover, the characteristics of compound K (CK), a PPD ginsenoside metabolite, resulting from the metabolic activity of enterobacteria, have been investigated. The effect of ginsenoside has been actively studied in leukemia but not in multiple myeloma (MM). Thus, the aim of study was to identify ginsenosides that have toxic effects against MM cells and to elucidate the underlying molecular mechanism. Methods: First, we screened the toxic effects of ginsenosides Rb1, Rb3, Rg1, Rg3, Rh1, Rh2, and CK at a concentration of 50 μM in several MM cell lines (ARH77, U266, and RPMI8226) after 24 hours of exposure. Furthermore, ARH77 cells were incubated with Rh2 and CK at 0, 20 μM, 50 μM, 60 μM, and 70 μM for 24 hours, and the DNA content at each stage of the cell cycle was detected. The potential cytotoxic effect of Rh2 and CK was investigated in normal hematopoietic stem cells (HSCs) isolated from healthy donors using primary peripheral blood stem cells (PBSCs). For this experiment, HSCs were isolated using a PBSC collection procedure after the recruitment of healthy donors. Briefly, granulocyte colony-stimulating factor was administered continuously until the white blood cell count exceeded the threshold of 1 × 109 cells/L. The subjects underwent leukapheresis once or twice using a blood cell separator. To quantify the production of PBSCs from each leukapheresis, flow cytometry was carried out to quantify CD34+ cells. To establish a human MM xenograft model, RPMI8226-RFP-FLuc cells (5 × 106 per mouse) were intravenously injected into 9-12-week-old male and female NOD/SCID IL-2Rγnull (NSG) mice. To assess the anti-MM effect of CK and Rh2 in the MM xenograft model, NSG mice were divided into the following treatment groups: Experiment set 1: no treatment (PBS control), CK (15 mg/kg/day), Rh2 (15 mg/kg/day), K (30 mg/kg/day), and Rh2 (30 mg/kg/day). Mice were treated with either CK or Rh2 (15 or 30 mg/kg/day) by intraperitoneal injection for 3 days in a week at a 1-day interval. Experiment set 2: no treatment (PBS control), CK (7 mg/kg/day), Rh2 (7 mg/kg/day), and Lenalidomide (1 mg/kg/day). Mice were treated with either CK or Rh2 (7 mg/kg/day) by intravenous injection for 3 days in a week at a 1-day interval. Lenalidomide (1 mg/kg/day) treatment was given by oral administration from day 14 for 5 consecutive days in a week, and it was repeated for 3 weeks at a 2-day interval in each week. Tumor growth was monitored weekly by bioluminescence imaging in the dorsal view; 10 min before imaging, mice were intraperitoneally injected with D-Luciferin (150 mg/kg/mouse). Results: The ginsenosides Rh2 and CK inhibited the cell growth, exerted cytotoxicity, and induced G1 phase cell cycle arrest in human MM cells. However, these treatments demonstrated no cytotoxic effect on the self-renewal and the differentiation capacity of normal primary PBSCs. This observation implied that the cytotoxic activity of Rh2 and CK might selectively target MM cells and that these ginsenosides are safe in other cell types. Finally, we studied the anti-MM effect of CK and Rh2 in a clinically relevant human MM xenograft model. PBS was given in the no treatment control group and all untreated tumor-bearing mice showed rapid tumor growth and severe plasmacytoma, which led to death within 7 weeks. Notably, mice treated with CK and Rh2 showed significant inhibition of tumor growth and a longer survival. Conclusions: Ginsenosides CK and Rh2 inhibited the growth of MM cells in an in vitro and in vivo model without any significant cytotoxic effect on the self-renewal and differentiation capacity of PBSCs. Thus, these ginsenosides could be used in MM treatment and can be combined with drugs without exerting any severe toxic effects. Keywords: Ginsenosides; Rh2; Compound K; Multiple myeloma Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Design of a novel integrated microfluidic chip for continuous separation of circulating tumor cells from peripheral blood cells

Cancer is one of the foremost causes of death globally. Late-stage presentation, inaccessible diagnosis, and treatment are common challenges in developed countries. Detection, enumeration of Circulating Tumor Cells (CTC) as early as possible can reportedly lead to more effective treatment. The isolation of CTC at an early stage is challenging due to the low probability of its presence in peripheral blood. In this study, we propose a novel two-stage, label-free, rapid, and continuous CTC separation device based on hydrodynamic inertial focusing and dielectrophoretic separation. The dominance and differential of wall-induced inertial lift force and Dean drag force inside a curved microfluidic channel results in size-based separation of Red Blood Cells (RBC) and platelets (size between 2–4 µm) from CTC and leukocytes (9–12.2 µm). A numerical model was used to investigate the mechanism of hydrodynamic inertial focusing in a curvilinear microchannel. Simulations were done with the RBCs, platelets, CTCs, and leukocytes (four major subtypes) to select the optimized value of the parameters in the proposed design. In first stage, the focusing behavior of microscale cells was studied to sort leukocytes and CTCs from RBCs, and platelets while viable CTCs were separated from leukocytes based on their inherent electrical properties using dielectrophoresis in the second stage. The proposed design of the device was evaluated for CTC separation efficiency using numerical simulations. This study considered the influence of critical factors like aspect ratio, dielectrophoretic force, channel size, flow rate, separation efficiency, and shape on cell separation. Results show that the proposed device yields viable CTC with 99.5% isolation efficiency with a throughput of 12.2 ml/h.

Microfluidics chip inspired by fish gills for blood cells and serum separation

In this paper, a microfluidic chip inspired by fish gills has been designed and fabricated in order to separate blood cells from serum. This microchip is modeled after fish gills which filter particles from fluids. In this way, the blood passes through a reservoir that contains several parallel rows of filter columns, which perform the filtering action. COMSOL Multiphysics software was used to conduct several simulations to optimize the pressure and velocity parameters of blood entering the microchip, and these parameters were used to determine the appropriate dimensions of the microchip. The simulation results indicate that the microchip is able to completely separate the cells from the serum, assuming a blood flow rate of 134 μl/s. With the help of the proposed filter, blood cells are separated from the plasma after 20 s and the aggregation occurs in the outlet reservoirs. In order to fabricate the microchip, the filter component made of polydimethylsiloxane (PDMS) was bonded to the copper substrate. In this paper a new copper to PDMS bonding process is proposed. Copper was chosen as the substrate because it allows the application of voltage to separate particles through the Dielectrophoresis method. The chemical etching method reinforced with noble metals was used to create micro holes on the silicon wafer, which are used to mold PDMS filters with a diameter of several micrometers. The main reservoir with a depth of 20 µm was created by the wet etching method. The reservoir was coated with silane coating and the oxygen plasma was utilized to bond the PDMS filters and the main reservoir. The copper substrate allows the microchip to be used with other electronic devices and circuits on printed circuit boards. Scanning Electron Microscopy (SEM) was used to observe the silane-coated copper surface, the micro holes on the silicon wafer, and the PDMS pillars. The topography and roughness of the copper surface before and after silane coating was evaluated through Atomic Force Microscopy (AFM). Optical Microscopy (OM) was utilized to observe the separation of the cells from the plasma. The results showed acceptable adhesion between copper and PDMS and good results for serum separation from blood cells.

Computational Inertial Microfluidics: Optimal Design for Particle Separation

Following the emergence of many blood transfusion-associated diseases, novel passive cell separation technologies, such as microfluidic devices, are increasingly designed and optimized to separate red blood cells (RBCs) and white blood cells (WBCs) from whole blood. These systems allow for the rapid diagnosis of diseases without relying on complicated and expensive hematology instruments such as flow microscopes, coagulation analyzers, and cytometers. The inertia effect and the impact of intrinsic hydrodynamic forces, the Dean drag force (FD), and the inertial lift force (FL) on the migration of particles within curved and complex confined channels have been explored theoretically, computationally, and experimentally. This study aimed to optimize the dimensions of a microfluidic channel for fast particle propagation and separation. Several spiral geometries with different cross-sections were tested using computational fluid dynamics (CFD) to separate two particle types representing RBCs and WBCs. The chosen three geometries consist of a single inlet, two outlets, and three spiral turns, each having a different cross-sectional height (120, 135, and 150 µm). Particle separation was successfully achieved in the 135 µm-height microchannel, while other microchannels demonstrated mixed particle types at the outlets.